The present invention relates to a printer that is used by being connected to an external device, such as a word processor or a personal computer.
Prior to the present invention, printers have employed printing conditions such as character style and printing pitch in response to printing data or control codes input from a personal computer or such. Further, some printers are capable of setting the printing conditions by operation of panel switches provided on the printer itself. The printing conditions set as described above are stored as flags in a storing means, such as a random-access memory (RAM), provided on the printer so that the printing may be executed according to the selected printing conditions.
When the printing is performed by a printer, confirmation of the printing conditions is useful. In the case of a printer having a display unit, the printing conditions to be confirmed are displayed on the display unit. On the other hand, in the case of a printer without a display, like the unit disclosed in Published Unexamined Patent Application Nos. 59-59487 and 60-15185, the printing conditions to be confirmed are printed as a fixed description on a printing paper. In a printer without the functions disclosed in Published Unexamined Patent Application No. 61-123565, confirmation is impossible except by printing some of printing data.
However, in the printers that display the printing conditions on the display unit and that print the printing conditions as the fixed description on the printing paper, the printing conditions are difficult to visually understand, so an operator is apt to misunderstand them. Therefore, the printing of the printing data must precede confirmation of whether the printing is proper or not. In addition, printing may deviate from the printing conditions due to an abnormality of a memory or such. In these conventional printers, the printing must actually be performed before the abnormality can be discovered.
Alternatively, a test printing facilitates a visual understanding, but when the printed appearance deviates from the printing conditions due to an abnormality of the memory or such, the operator cannot discover the abnormality because the printing conditions are not printed. As a result, an undesired printing is conducted.